problem with merc 9.9

[joeyquicksand*]

I think the gears in the lower unit are shot because the motor runs well, but dosent kick any power out. Runs ok at a very slow speed, but its like the more juice i give her, the higher the rpm of the motor is, but i don't move faster, and i'f i keep reving it, the motor will probably blow.

Anyone know what I should do?

[Ralph Wiggum]

Sounds like the hub in your prop might be spun. Make a mark that goes across the hub and onto the prop, take the motor out for the cruise, and if you come back and the marks are not lined up, you've got a spun hub. They can be replaced by a prop shop. It might be about the same price for a new prop, though.

[joeyquicksand*]

I noticed that when I pulled out, the lower unit was hot, and leaking lower unit oil our of some drain hole towards the upper end of the lower unit... looked milkier than when i put it in... the lower unit was hot, but the engine wasn't...

[Surface Tension]

Definitely drain the lower unit and look for milky oil or no oil. If you have the above you'll need new seals. In this case leaking milkly lower unit oil up high would most likely be driveshaft seals(under the water pump) in which case you'll change the impeller at the same time.

Hopefully the heat is from the prop slipping on the hub and not internal damage in the lower unit. Look for metal shaving in the drain oil.

[marine_man]

leaking lower unit oil our of some drain hole towards the upper end of the lower unit

Follow Frank's advice, but this typically isn't a good sign for your lower unit. It very likely may be time for new seals.

marine_man

[joeyquicksand*]

I really appreciate all you guy's help... thanks, i'll report what i find, and either look for more answers, or tell you how the repair went.

[boatfixer]

I'm hopeing that you found two different problems

1. Bad seals letting water in.

2. Spun hub

It's been my experience that if you have a gear failure to the point that it will still catch at an idle but wont hang on at higher speed, you wont find milky oil. you will find burned oil-black and stinky that is also mixed up with lots of little shiny pieces that once used to be gear teeth. If not burned I would think you will at least find metal shavings.

Much cheaper to re-hub and re-seal than it is to replace gears.

Lets hope it's not gear failure, be sure to let us know what you find.

[MN Angler]

I was just out using my motor its a late 70s evinrude and it just started doing the same thing as joeyquicksands. So do I take the prop off and is the hub directly under that?

[Surface Tension]

Consider the prop as two parts. The hub is pressed into the prop.